Supernatural and Grimm Crossover (Working Title)
by superwholock-slashlover
Summary: Liz Winchester, Dean's twin sister, works at the Portland Police Department as Detective Nick Burkhardt's Partner. When Sam, Dean, and Cas show up on her doorstep, adventure and insanity soon follow. The only characters I own are Liz and a few other OCs. I do not own SPN or Grimm. (rated for language and some situations in later chapters) Pairings: Destiel, Sabriel, and OC/Nick
1. Chapter 1

Now

The sky was pitch black, the rain poured down in thick sheets, making it damn near impossible to see the road. I was driving home from another long day at the precinct. As I drove, I went over the events of the past few months in my head. Maybe that's where I should start this story. So fasten your seatbelt, it's going to be a bit of a bumpy ride.

3 Months Ago

"Winchester," I said into my cellphone.

"What the hell, Liz? Since when do you call me by our last name?" I heard a very familiar voice, albeit one I hadn't heard in a few years, on the other end.

"Dean-o! Sorry, I'm just used to answering my phone by saying our last name. It's a work-related habit." I rolled my eyes as my brother sighed, I could hear irritation in the sigh. "And how the holy hell did you get my number? As far as I can remember, only a few people have it."

"Got it off of Bobby, after he called me an 'idjit' for not having my own twin's number. So what have you been up to?"

Just as I was about to respond, my partner Nick Burkhardt came bursting through my front door. He slammed the door shut and ran into the living room, diving behind the couch.

"Hold that thought, Dean. My partner just ran in here like a bat out of hell." I entered the living room calmly, holding the phone against my shoulder. "Nick, what the hell, man? You look like you've been chased by a rogue Blutbad."

"Blutbad? What the hell is that?" Dean's voice came through the phone. I ignored him.

"Worse than that. I just broke up with Juliette because it's getting too stressful hiding the fact that I'm a Grimm. I should have broken up with her when Aunt Marie told me to do it." Nick's voice was slightly muffled, as though he had a pillow over his face, which wouldn't surprise me.

"Okay. But that still doesn't explain why you're hiding in my living room."

"She took it pretty bad. When I said that I couldn't tell her exactly why I can't be with her, she automatically assumed that I was cheating on her. Then she accused me of cheating with Adalind."

"Adalind Schade?! What the fuck! Why would she think you were cheating with that bitch of a Hexenbiest? You don't even spend time around her!"

"Liz? Are you gonna talk to me at all or should I just hang up?" I jumped. I had nearly forgotten that I was still on the phone with Dean.

"Sorry, bro. I was just worried that my partner was hiding from a criminal or something."

"Why would he do that?"

"Well, criminals don't exactly like cops, now do they?" I heard what sounded like sputtering and choking. "Dude, did you just do a spit-take?"

"Yeah," he coughed a little. "I did. Since when are you a cop? Especially considering how we were raised."

"Technically, I'm a detective. But in answer to your question, I've been on the force for three, no four years. I started right after I left you and Sammy." I opened the fridge, and took out two beers. I popped the top off of one. "Sorry about ignoring you for a little while there. How are you and Sam doing? Did you find Dad?"

"Yeah, we found him a couple years ago. He died, but he went down fighting. Sam and I are doing alright, all things considered."

"What do you mean, 'all things considered'?" I lowered my beer from my lips.

"Well, you see Sam died and I made a deal to save him. The fucker gave me one year. Then I went to hell. Then after four months topside, which is forty years in the pit, an angel pulled me out and now we kinda had to stop the apocalypse. This is a bit weird to talk about over the phone. Where do you live now?"

"Portland, Oregon. Just stop by the station next time you're in town. Just ask for Detective Winchester at the desk. Now if there's nothing else, I need to help sort out my partner's love life. Later, bro."

"Talk to you soon, sis."

I grabbed the second beer off the counter and made my way into the living room.

"Nick, get your ass out from behind that couch and have a beer. Especially since if Juliette does decide to come here looking for you, it'll look a hell of a lot stranger if you're hiding."

"Thanks, Liz. It's just that-" a knock at the door cut him off. "If that's Juliette-"

I cut him off this time, "You're here but not in the mood to talk." I opened the door, fully expecting to see Juliette. Who was actually at the door made me nearly drop my beer. "Sam? Dean? How the holy fucking hell did you get here so fast?"

"Cas brought us, and Baby, via 'Angel Air.' We figured it would be better to talk now rather than later. Can the three of us come in?" Dean seemed a bit impatient. I looked behind him at my driveway, and sure enough there was a very familiar black Chevy Impala.

"First things first, Christo." Their eyes didn't change. I pulled a silver dagger from my belt and nicked each of them. "Okay, you're clean. Come on in and shut the door behind you." I led them to the living room, where Nick was still sitting on the couch.

"Nice place. So who's this?" Sam always was the more straight-forward of my brothers, for which I was extremely grateful.

"Right, introductions. Sam, Dean, this is my partner Nick Burkhardt. Nick, the sasquatch in plaid is my younger brother Sam, and the idjit in leather is my twin brother Dean. However, I don't know the cutie in the trench-coat."

"My name is Castiel. I'm an angel of the Lord."

"I took a good look at Castiel, or as Dean had called him, Cas. He was dressed in a suit that was the wrong size, a backwards blue tie, and a somewhat dirty tan trench-coat. He had messy dark hair, bright blue eyes, and a little scruff. He didn't look much like an angel to me.

Before meeting Cas, the only other angel, well archangel, I'd met was Gabriel. From what I remember, Gabriel said that he and my brothers don't exactly get along the best. Which is why I refrained from mentioning him, for the time being at least; that and Gabe had told me that my brothers thought he was dead from when he fought Lucifer.

Author's Note: This is my first fic. Please review and tell me what you think.


	2. Chapter 2

For anyone who may be wondering, this story takes place somewhere between seasons 5 and 7 of Supernatural and around season 3 of Grimm, but Nick never told Juliette that he's a Grimm.

"If you guys wanna talk, let's all go in the kitchen," I said as i grabbed my apron from the hook I keep it on.

"Why?" Sometimes I wonder if Dad dropped a shotgun on Dean's head when we were kids.

"If you want a burger, you have to help make dinner. Nick, your apron should be where you usually keep it." I opened the fridge to get the necessary ingredients for dinner. "Personally, I find it hilarious that Juliette thinks you're having an affair with Adalind. After all, you'd sooner decapitate that bitch than kiss her."

Dean, Sam, and Cas exchanged concerned looks. "Why would he decapitate her? Is she a vampire?" Of course Sam would come to that conclusion.

"Nope, she's a Hexenbiest, which is much worse." My brothers looked at me, highly confused.

However, Cas had a look of realization on his face. "I'd heard something about a large number of Wesen in the Portland area. I just didn't know if it was true or not. My brothers and sisters were discussing Wesen over what Dean calls 'Angel Radio.' I didn't participate in the conversation, but it was highly informative."

"What the fuck is a Wesen?!" Dean seemed highly annoyed. He and I both get like that when we feel like we're out of the loop.

"Wesen look like ordinary people. But in reality, they're creatures. Some are friendly and harmless, while others are highly dangerous. Nick is what's known as a Grimm, he's descended from the Brothers Grimm and can see a Wesen's true form. Hexenbiests look like beautiful women when in human form, but when they woge, or change, they look kinda corpse-like and ugly. They're basically witches. Sam, could you set the table please?" I handed him a stack of plates and silverware. "Dean, remember that thing about me that Dad mentioned when we were kids?"

Dean nodded. "That you were born with the ability to see things differently than Sam and I. Why do you ask?"

"Because that ability is actually that I'm a Grimm. Somewhere on Dad's family tree, someone married a descendant of the Brothers Grimm. The 'Grimm gene' often skips a generation or two. According to a journal of our grandfather's, he was a Grimm. Dad gave me the journal when I turned thirteen and I started showing signs of being a Grimm. That's why I work so well with Nick, we're both Grimms."

"So what's it like being a cop? I mean other than the Grimm thing, it's gotta be a huge difference from hunting."

"It's a bit boring sometimes, mostly when we have to do a bunch of paperwork, but generally when we have a homicide to investigate, it ends up being Wesen-related. It can be a little annoying, especially since Wesen have a tendency to freak out when they realize we're Grimms. But, yeah, it's definitely different from being a hunter." I carried the burgers to the kitchen table. "Enough talk, let's eat."

1 Hour Later

"So, what exactly has been going on-" I was cut off by the sound of fluttering wings.

"Hey, Lizzie! I need to borrow your Grimm-ness for a…" Gabe trailed off upon seeing my brothers in the living room. "Um, hi guys." He had the look on his face that a kid gets when caught with a hand in a cookie jar, or in Gabe's case, a candy jar.

"What the hell, man! When we watched that awful porno you told us you were dead! How the fuck are you alive?" Dean definitely knows how to get straight to the point.

"Anyone up for another round of beers? Or maybe something stronger?" I looked sheepishly at my brothers.

"Wait, you _knew_ that Gabriel was still alive? Why didn't you mention it to us when we got here?" Sam seemed a little too upset, especially since Gabe had told me about the whole Mystery Spot ordeal he'd put my brothers through. It surprised me that Sam actually seemed to care about someone who had killed his older brother repeatedly in one day.

"Yeah, I knew. But the reason I didn't tell you was because of the fact that Gabe had done so much shit that either annoyed or pissed you guys off, and I didn't want to stir up any unnecessary trouble." I poured glasses of whiskey for everyone, passed them around, and took a sip of mine. "Gabe what the fuck do you want this time? I'm not interested in being your personal errand girl today. Yes, we're friends, but I don't feel like running around Portland trying to find you specific brands of chocolate."

"Actually, I just wanted to see if you and Nicky wanted to go for drinks. And since we're pretty much already doing that, I don't need to ask. So, Samsquatch, Dean-o, how's it goin'?" Why Gabe needs to use nicknames for everyone, I'll never know.

Sam looked like he wanted to either punch Gabe or kiss him. Sam stood up, grabbed Gabe by the collar of his jacket and slammed their mouths together. Every one of us stared wide-eyed as the two of them made out.

Dean snapped out of the trance-like state first and cleared his throat. "Um, Sam, if you're gonna do that, get a room."

Sam pulled away from Gabe. "Now you know how I feel," he said, smirking at Dean. He nodded his head toward Cas, which caused Dean and Cas' faces to turn bright red.

"Wait a minute, are you saying that all three of us like men?" I was stunned, both my brothers had only had girlfriends as far back as I could remember. I felt an arm across my shoulders. "Nick, was there more to breaking up with Juliette than your being a Grimm?"

"Maybe a little." Nick looked at me a bit sheepishly. "I also broke up with her because there _is_ another woman on my mind but it's not Adalind."

"Me? You broke up with Juliette because you're falling for me? I mean I've had a crush on you since the day we met, but I never thought you-" I was cut off by Nick pressing his slightly chapped lips against mine. And all thought processes stopped for however long that first kiss was.

Author's Note: I know, not the best place to end the chapter. But I'm tired and need to sleep. 'Night all. I'll post another chapter soon.


End file.
